The present disclosure relates to a separator having a vertical axis of rotation and a drum with solids discharge openings in a single-cone or double-cone centrifugal space. The separator also includes a disk stack of super-imposed conical disks. The discs have bores forming at least one channel in the disk stack. The separator includes a distributor having a shaft concentrically surrounding a drum axis and a lower base section which expands radially. In the lower base section, one or more distributor channels are distributed in the form of bores.
It has been known for a long time to arrange disc stacks consisting of a plurality of discs situated axially above one another in the direction of the disc axis concentrically to the machine or drum axis in centrifugal drums of separators. This is known from the field of separators with drums with a vertical axis of rotation and solids discharge openings in a pulp space outside the disc stack.
In the case of separators with a vertical axis of rotation, a feeding of the product into the centrifugal drum takes place along the drum axis through a feeding pipe and radial distributor channels connected behind the feeding pipe. The product enters the centrifugal drum into the disc stack consisting of separating discs which are generally situated closely above one another but are nevertheless spaced relative to one another in the area of the essential disc surfaces and, as a rule, are conical. At the discs, heavier solids generally accumulate on the bottom side and move to the outer circumference of the disc stack, while the liquid flows toward the interior, in, for example, a two-phase liquid-solid separation.
For the implementation of a liquid-liquid-solid separation, that is, a three phase liquid-solid separation, it is also known to provide the disc stack with so-called rising channels, which are formed of bores in the discs of the disc stack situated directly or with a twist (see German Patent Document DE 100 55 398 A1) above one another.
From U.S. Patent Document US 993,791, a chamber centrifuge is known which has no solids discharge openings and in which the diameter of the bores changes within a disc stack. Or, the orientation of the openings is changed from one disc to the next in that a disc holding contour sloped toward the axis of rotation is arranged, for example, at the shaft.
The discharge of the liquids generally takes place in areas radially on the inside or radially on the outside with respect to the discs of the disc stack. It is also known to construct discharge channels for the liquid phase(s) by means of bores particularly close to the inner circumference as well as close to the outer circumference of the disc stack in the disc stack (see, for example, German Patent Document DE 284640).
It is also known to equip the discs with so-called spacers in the manner of webs and/or small tips or points which, on the one hand, provide a mutual spacing of the discs and, on the other hand, influence the flow conditions in the disc stack. Spacers can be placed between the discs which preferably are separate from the discs. The discs are generally held in grooves on a distributor shaft or in other disc holders.
The present disclosure relates to optimizing the flow conditions in the drum of a separator by simple constructive devices.
The present disclosure further relates to a separator having a vertical axis of rotation and a drum with solids discharge openings in a single-cone or double-cone centrifugal space. The separator also includes a disk stack of super-imposed conical disks. The discs have bores forming at least one channel in the disk stack. The separator includes a distributor having a shaft concentrically surrounding a drum axis and a lower base section which expands radially. In the lower base section, one or more distributor channels are distributed in the form of bores. A diameter of the at least one channel inside the disc stack, located above the disc which is the lowest in a flow direction, is not constant and/or is arranged to be sloped with respect to an axis of rotation of the drum. The bores of the at least one distributor channel are not radially oriented with respect to the drum axis in the drum.
Illustrative embodiments are described herein.
As noted above, a diameter of the at least one channel, within the disc stack above the lowermost disc in a flow direction, is not constant and/or the at least one channel is arranged in a sloped manner with respect to the axis of the drum. The bores of the at least one distributor channel do not have a radial orientation to the drum axis in the drum.
According to the present disclosure, it becomes possible, for example, in the case of a centrifuge with a pulp space outside the disc stack, with a piston valve arrangement or solids discharge nozzles to optimize the flow conditions in the drum. Further, according to the present disclosure, a combination of one or more of the above-noted features, that is distributor and channel geometry and/or channel orientation, may be utilized for optimizing the flow conditions in the centrifuge in a constructively simple manner and to optimally adapt them to the product to be processed.
It is noted that German Patent Document DE 38 80 19 shows a centrifuge of a different type with an inlet pipe which is not concentrically arranged.
A geometry of the bores of the discs of the at least one channel, which may be a rising channel, varies in the channel in such a manner that, during the operation, gaps between the discs are uniformly charged with liquid over the entire height of the disc stack. As a result of this advantageous measure, the flow conditions in the centrifuge are clearly optimized. Thus, not only a simple widening of the bores “from one disc to the next” is implemented but a flow-dependent optimization, in the case of which the bores can be designed to be constant over several discs and will then, for example, widen. In this manner, each disc separately can have an optimal design. On the production side, this can be easily implemented by laser cutting the bores in the metal sheet of the discs.
For example, the diameter of the channel can change in steps at a distance of several discs or continuously from one disc to the next and decrease in the flow direction. It is expedient for the diameter to decrease, for example, continuously, in the flow direction.
The bores may have an arbitrary shape. An optimal shape is determined by a person skilled in the art by tests as a function of the product. Thus, the bores may have a polygonal or round or curved shape in any alignment.
In an illustrative embodiment, each channel includes several bores which, in turn, advantageously may also form a perforated pattern for example, distributed on the circumference on a circle or an ellipse in the discs.
It is within the scope of the present disclosure that the at least one channel, which may be sloped, extends in a curved manner with respect to the drum axis in the disc stack.
In such an embodiment, the at least one channel may comprise a rising channel for feeding the product into the disc stack and/or, at least one discharge channel for discharging the liquid phase from the disc stack. The optimized design of rising and discharge channels also contributes to improving the flow conditions.
One of the discharge channels for discharging various liquid phases is constructed close to the inner circumference or close to the outer circumference of the disc stack and/or is constructed inside the disc stack. The flow direction extends in the direction of the liquid discharges of the drum, with the vertical orientation generally in the upward direction.
Based upon the present disclosure, it becomes possible to optimize the further development of the channels of a separator with a vertical axis of rotation as a function of the product and the machine in order to improve the parallel connection of the discs of the disc stack and to optimize the flow conditions. That is done in order to, for example, compensate separating zone displacements because of pressure differences in the disc stack, for example a radial position and to reduce instabilities in the disc stack, for example, in the circumferential direction.
The present disclosure also includes providing a distributor with at least one distributor channel constructed as a bore in a distributor base. Such a distributor channel is not oriented radially in the drum, which, in turn, optimizes the flow conditions in a simple manner as a function of the product.
According to the present disclosure, the distributor channels may be oriented in a sloped manner against the rotating direction of the drum or under certain circumstances in the rotating direction of the drum.
The distributor channels, which are formed by bores relative to the radial line through the drum axis in a radially interior bore section against the rotating direction of the drum, advantageously may be oriented to be sloped in a lagging manner.
As a result of that orientation, the flow conditions are further optimized in combination with the measure that the distributor channels lead in a further bore section into the drum, which bore section is oriented upwards in the drum and leads out directly below a rising channel of the disc stack into the drum. In addition, a more careful acceleration and an optimal entry of the centrifugal material into the rising channels is ensured.
The distributor channels may have an expanding round or a slot-type outlet which extends tangentially in or against the rotating direction of the drum and/or is directed upward in the drum.
Other aspects of the present disclosure will become apparent from the following descriptions when considered in conjunction with the accompanying drawings.